The present invention relates to a cutting tool for milling, boring or turning, in which a blade is clamped in the slotted end of a holder shank by means of a clamping screw which loosely extends through a hole in the blade and which is effective to squeeze the slotted end of the holder shank into gripping engagement with the blade. Furthermore, the present invention relates to a blade which is to be clamped in the slotted end of said holder shank.
According to U.S. Pat. No. 2,621,548 a cutting tool of the abovementioned type is previously known in which one side of the slot is provided with a rib which is to be received by a recess in the blade. The concave surface of the recess coincides with the convex surface of the rib whereby the radial positioning of the blade will occur directly as the blade is inserted in the slot of the holder. However, the surfaces have to be carefully machined to obtain a precise position and the surfaces are susceptible to wear. Furthermore, the blade is provided with a central hole to receive a screw that has to be fully unscrewed before any change of blade can be made.
The object of the present invention is to provide a cutting tool which solves the above-mentioned problems in a simple way. The essential part of the invention is that contact surfaces between a side of a slot and a recess of a blade are radially displaced relative to each other and that the contact surfaces are converging towards the other side of the slot in order to radially center the blade in the slot when tightening the screw. The screw is received through a groove in the blade allowing the blade to be slidably mountable in the slot without unscrewing the whole screw.